Photofission ofTh232with 9, 15, and 38 MeV peak bremsstrahlung

Mass distribution in the bremsstrahlung-induced fission of 232Th, 238U and 240Pu

“…The calculation of saddle point configurations against the mass asymmetric deformation by Moller [95] showed a different type of potential barrier for 232 Th compared to 238 U, which was mentioned before. Thus, the observation of a triple humped mass distribution from the present and earlier work in bremsstrahlung [59,60], re- Table 3 Nuclear spectroscopic data and yields of fission products in the 10 MeV bremsstrahlung-induced fission of 240 Pu. actor neutron- [14][15][16] and mono-energetic neutron-induced [38][39][40][41][42] fission of 232 Th compared to that of 238 U and 240 Pu is due to a different type of potential barrier.…”

“…In the electromagnetic fission of lighter actinides [52][53][54], higher yields of fission products around mass numbers 133-135 corresponding to a most probable charge of 52 have been observed. Similarly, higher yields of fission products around mass numbers 133-135 in the 3 and 14 MeV mono-energetic neutron-induced [28][29][30][31][32][33][34] and in the 9, 15 and 31 MeV bremsstrahlunginduced [59] fission of 232 Th have also been observed earlier. However, in the 6.44-13.13 MeV bremsstrahlung-induced fission of 232 Th [60], yields of fission products are more pronounced around mass numbers 143-145 compared to mass numbers 133-135, which is contradictory to the earlier observations [23][24][25][26][27]59].…”

“…[60] that a third peak for the symmetric products was observed in the 6.44-13.13 MeV bremsstrahlung-induced fission of 232 Th. This is not clear from the radiochemical data on the 9 and 10 MeV bremsstrahlunginduced fission of 232 Th [59] due to a lack of sufficient data around the symmetric region. The observation of a third peak of symmetric products in the bremsstrahlung-and neutron-induced fission of 232 Th is interesting in view of probing the potential energy surface.…”

“…Similarly yields of fission fragments in the excitation energy range of the GDR region due to electromagnetic fission in inverse kinematics [52][53][54] are available for neutron-deficient lighter actinides such as 214-223 Ac, 220-229 Th, 224-232 Pa and 231-234 U. On the other hand, yields of fission products in the bremsstrahlung-induced fission of actinides are available in a broad energy range for a limited number of actinides including 232 Th [55][56][57][58][59][60], 235,238 U [61][62][63][64][65][66][67][68][69][70][71][72][73][74] and 240,242,244 Pu [75][76][77][78]. Most of the yield data on fission products available in the 9 MeV to several GeV bremsstrahlung-induced fission of 232 Th [55][56][57][58][59] and 235,238 U [61][62][63][64][65][66][67] are based on radiochemical separation and beta counting or γ -ray spectrometric techniques.…”

Symmetric and asymmetric yields in the photofission of232Th,235U,238U and239Pu

“…Only using future high duty cycle electron accelerators these difficulties can be avoided by constructing intense mono-energetic "tagged photon" sources or by doing (e, e'f)-coincidence experiments. In the past some photofission measurements of mass distributions had been performed with radiochemical methods and catcher foil techniques on 232Th and 238U for different bremsstrahlung endpoint energies (see [4,5] …”